There is a need for determining when class 2-8 vehicles are loaded such that the vehicle Gross Vehicle Weight (GVW) limits are exceeded due to inadvertent or deliberate weight added to the design feature for a vehicle. Presently there are no easily installed sensor devices or methodologies that enable such a determination. In commercial applications where vehicle up fitters start with a bare chassis, add vehicle structure and then allow the ultimate operator/user to add additional weight such as tools or materials, the vehicle can easily be overloaded in excess of the manufacturers intended weight limits. Such overloading produces both unsafe operating conditions as well as contributing to vehicular wear and tear in excess of its intended use.
A need exists for an inexpensive highly reliable sensor that can be fitted to a vehicle chassis, connected to the vehicle data bus and be used to continuously monitor and determine the operating condition of the vehicle.
More particularly, with respect to the operation of fleet vehicles there are three problems. The first problem is one of reliability. If a vehicle is overloaded then parts of the truck are strained and various mechanical systems can break down. Thus truck reliability is directly proportional to any overloaded conditions that may occur.
Second is a safety issue. If the trucks are overloaded they do not handle particularly well. If for instance one considers a boom truck, and if the right side of the truck has 1,000 pounds more than the left side, then if the boom operator is extending in that direction he will be exceeding the safety limits of the truck. Thus, weight distribution and thus truck leveling can involve a safety issue.
Third is a legal compliance issue meaning whether or not the maximum gross vehicle weight has been exceeded.
While trucks are provided with a gross vehicle weight rating such as 30,000 or 40,000 lbs, instructions to the operator simply not to exceed this rating are ineffective as there presently is no continuous monitoring of the loaded weight of the vehicle.
Moreover, when trucks are manufactured they are given a gross vehicle weight rating which does not take into account any additional equipment that is added to a truck. For instance, any additional equipment that is added to the truck is not taken into account in the weight rating. By way of example, customers will start to put tools and equipment on a newly bought or leased truck and may for instance fill up utility bays with equipment. However, once the truck leaves the factory there is no way to easily ascertain whether the loaded truck is within the maximum gross vehicle weight rating assigned to the truck, or for instance how the truck is maintained with respect to the rating.
It is noted that a 40,000 pound truck is a great deal more expensive than a 35,000 pound truck, and cost is a major issue with fleets seeking to buy the cheapest vehicle that they can. As a result of buying a cheaper truck, owners or operators typically overload them. It has been thought that perhaps as many as 60% of the vehicles go out on the road at one time or another where the vehicle's gross vehicle weight exceeds the maximum.
Thus, for instance, while the trucks may leave the factory in a compliant condition they are essentially shipped as an empty truck. Typically utility operators decide what is going to be carried on a truck with no particular thought to the final weight of the loaded truck. In short, there is no convenient way to give a truck operator an immediate understanding that his vehicle is overloaded or that uneven loading or a load shift has occurred which may result in tipping or unsafe operation.